diff --git a/usr.bin/dtc/fdt.cc b/usr.bin/dtc/fdt.cc
index b6e7d56d7e4..6f27c9cb0b5 100644
--- a/usr.bin/dtc/fdt.cc
+++ b/usr.bin/dtc/fdt.cc
@@ -30,6 +30,8 @@
  * $FreeBSD$
  */
 
+#define __STDC_LIMIT_MACROS 1
+
 #include "fdt.hh"
 
 #include <algorithm>
@@ -281,6 +283,12 @@ property::parse_cells(input_buffer &input)
 				valid = false;
 				return;
 			}
+			if ((val < 0) || (val > UINT32_MAX))
+			{
+				input.parse_error("Value out of range");
+				valid = false;
+				return;
+			}
 			push_big_endian(v.byte_data, (uint32_t)val);
 			input.next_token();
 		}